Re: [RFC] delayed allocation for ext4
From: Alex Tomas
Date: Thu Dec 28 2006 - 23:57:14 EST
>>>>> David Chinner (DC) writes:
DC> So that mean's we'll have 2 separate mechanisms for marking
DC> pages as delalloc. XFS uses the BH_delay flag to indicate
DC> that a buffer (block) attached to the page is using delalloc.
>> well, for blocksize=pagesize we can save 56 bytes on every page.
DC> Sure, but it means that ext4 w/ delalloc won't work on lots of
it does not currenly. but I'm going to implement that. not sure
whether it's worth to have two different codepaths for
block size=page size and block size < page size.
DC> FWIW, how does this mechanism deal with block size < page size?
DC> Don't you have to track delalloc on a block basis rather than
DC> a page basis?
>> I'm still thinking how better to deal with that w/o much code duplication.
DC> Code duplication in ext4, or across all filesystems?
given what Andrew said about moving the code into VFS, it's more
about all filesystems.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/